America was once a great industrial nation, with steel mills, factories, and with railroads that reached to every corner of every state. But now that day is past. The steel mills and the factories have moved to other countries where the labor is cheaper.

Industrial archeology is the study of the remains left behind by this gradual transition. Some industrial sites are preserved for their historic value. Some won't be torn down until the land they occupy is needed. And some are so monstrous that there is not much you can do but just leave them there.

These mills made the steel used to build the Empire State Building and the Golden Gate bridge. Once a proud symbol of our nation's might, now abandoned.